This invention is directed to a reinforced and insulated flexible hose made with elastic materials and flexible reinforcement strands, together with the apparatus and method for making the hose.
Prior technology consists of two known methods of insulating hoses. Each of these methods apply a sponge or foam material by a secondary operation. In the first prior method, a hose having any type of construction or material is selected for the insulation application. A foam or sponge tubular extrusion is produced with the inside diameter slightly larger than the outside diameter of the hose. This extrusion is slid over the hose. Generally, no adhesive is applied to the outside of the hose. The disadvantages of this construction include the fact that this method of manufacture is only successful with short lengths, generally under about 12 feet in length, depending on the sizes, materials and clearances. Of course, it is difficult to slide the foam extrustion over the hose, and this results in high labor costs due to the assembly time. With the resulting two-piece construction, there is no adhesion between the insulation and the hose, and this results in a structure which is more difficult to package and with a weight disadvantage due to the method of construction. Generally, the hose is purchased from one source, and the extruded outer tubular insulation layer from another, resulting in a difficult problem in achieving the size tolerances which permit practical assembly.
The second prior art method utilizes a flat, precut width and length of an extruded or molded flat, flexible foam or sponge insulation material. This material is wrapped around a previously extruded, flexible hose. A longitudinal butt or lap seam is adhesively bonded to complete the hose assembly. The disadvantages of this type of construction include the fact that no adhesion of the insulation material to the hose is achieved. Another disadvantage is the the need to form a joint of the porous insulation material with its adhesive joint, because such joints are difficult to form in a secure fashion. Generally, this method is used to cover only short lengths of hose, possibly due to the high cost of labor in connection with the insulation material layer application and adhesive joining. Manufacturerers of such hoses usually buy the hose and insulation material from different sources, with the result of more difficult coordination and assembly. This often results in a weight disadvantage for this type of construction. It is not commercially supplied in lengths over 50 feet.
Thus, there is a need for an economic and secure reinforced insulated hose produced on a continuous basis with unitary construction without adhesive joints in the insulation layer. Furthermore, it is desirable to have a long hose so that long runs can be made with such an insulated hose without having to join several short lengths of hose.